Single CuO/Cu2O/Cu Microwire Covered by a Nanowire Network as a Gas Sensor for the Detection of Battery Hazards
Single CuO/Cu2O/Cu Microwire Covered by a Nanowire Network as a Gas Sensor for the Detection of Battery Hazards
复制标题
DOI：
10.1021/acsami.0c09879
复制
发表时间：
2020-09-16
影响因子：
9.5
通讯作者：
Hansen, Sandra
中科院分区：
文献类型：
--
作者：
Lupan, Oleg;Ababii, Nicolai;Hansen, Sandra
在这项研究中，一种策略，以制备CuO/Cu 2 O/Cu的微米线，完全覆盖的纳米线（NW）网络，使用一个简单的热氧化过程开发。将CuO/Cu 2 O/Cu微丝固定在具有Cu微粒的Au/Cr垫上。在425摄氏度的热退火后，这些CuO/Cu 2 O/Cu微丝被用作室温2-丙醇传感器。这些传感器显示出不同的主导气体对工作温度的响应，例如，在175 ℃下对乙醇的灵敏度较高，在室温和225 ℃下对2-丙醇的灵敏度较高，在接近300 ℃下对氢气的灵敏度较高。在此背景下，我们提出了这种基于CuO/Cu 2 O/Cu的三合一传感器的传感机理。X射线衍射（XRD）研究表明，在氧化过程中的退火时间会影响传感器的化学外观，而反射的强度证明，对于在425 ℃下氧化1小时的样品，主要相是Cu 2 O，而在进一步增加退火时间至5小时，CuO相成为主导。用透射电子显微镜（TEM）、高分辨透射电子显微镜（HRTEM）和选区电子衍射（SAED）证实了Cu 2 O-壳/Cu-核和表面上的CuO NW网络的晶体结构，其中（HR）TEM显微照片揭示了单斜CuO相。密度泛函理论（DFT）计算为不同气体分子与最稳定的CuO顶面的相互作用带来了有价值的输入，揭示了由于气体分子与顶面的相互作用而引起的强结合、电子带隙变化和电荷转移。这项研究显示了非平面CuO/Cu 2 O层状异质结构作为一种明亮的纳米材料用于检测各种气体的重要性，由工作温度控制，这里提出的见解将在通过简单的纳米技术制造新的p型传感器件中具有重要价值。
In this study, a strategy to prepare CuO/Cu2O/Cu microwires that are fully covered by a nanowire (NW) network using a simple thermal-oxidation process is developed. The CuO/Cu2O/Cu microwires are fixed on Au/Cr pads with Cu microparticles. After thermal annealing at 425 degrees C, these CuO/Cu2O/Cu microwires are used as room-temperature 2-propanol sensors. These sensors show different dominating gas responses with operating temperatures, e.g., higher sensitivity to ethanol at 175 degrees C, higher sensitivity to 2-propanol at room temperature and 225 degrees C, and higher sensitivity to hydrogen gas at similar to 300 degrees C. In this context, we propose the sensing mechanism of this three-in-one sensor based on CuO/Cu2O/Cu. Xray diffraction (XRD) studies reveal that the annealing time during oxidation affects the chemical appearance of the sensor, while the intensity of reflections proves that for samples oxidized at 425 degrees C for 1 h the dominating phase is Cu2O, whereas upon further increasing the annealing duration up to 5 h, the CuO phase becomes dominant. The crystal structures of the Cu2O-shell/Cu-core and the CuO NW networks on the surface were confirmed with a transmission electron microscope (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED), where (HR)TEM micrographs reveal the monoclinic CuO phase. Density functional theory (DFT) calculations bring valuable inputs to the interactions of the different gas molecules with the most stable top surface of CuO, revealing strong binding, electronic band-gap changes, and charge transfer due to the gas molecule interactions with the top surface. This research shows the importance of the nonplanar CuO/Cu2O layered heterostructure as a bright nanomaterial for the detection of various gases, controlled by the working temperature, and the insight presented here will be of significant value in the fabrication of new p-type sensing devices through simple nanotechnology.